Airplane crash switch



Oct. 30, 1951 R. H. HoDGxNs r-:TAL

AIRPLANE CRASH SWITCH 4 Sheets-Sheet 1 Filed March 26, 1948 Rober! H.Hodg/'ns Clifford J. McGill/'way l JNVENTORS. y

oct. 3o, 1951 R, H, HODGJNS ETAL 2,573,335l

AIRPLANE CRASH SWITCH Filed March 26, 1948 4 Sheets-Sheet 2 Fig?.

Robert H. Ho'a'gins Clifford J. Mc Gill/'way INVENToRs.

Bf wf/hws oct. 3o, 1951 R H, HODGWS ETAL 2,573,335

AIRPLANE CRASH SWITCH Filed March 2e, 1948 4 Sheets-sheet 3 Fig. 3. Fig.5

38 2 68 69 38 /50 40 e Y /50 I /22 1l r 32 i 68 Robert H. Hodg/'nsClifford J. McGill/'way JNVENToRs R. H. HDGlNs E-rAL v 2,5735335 Oct.30,' 1951 AIRPLANE CRASH SWITCH Filed March 26, 1.948

Robert H. Hodg/'ns Clifford J.. McGill/'way INVENTORS.

Patented Oct. 30, 1951 `AIRPLANE CRASH SWITCH :Robert H. Hodgins,Vancouver, British Columbia, and .Clifford J. McGillivray, NewWestminster, British Columbia, Canada Application March26, 19.48, SerialNo. 17,206

Y14: Claims.

vThis invention appertains to novel and useful improvements inattachments for aircraft.

Anobject of ythis invention is to break the circuit of the usualaircraft electrical system and simultaneously spray a lire extinguishingcomposition on various appurtenances-,contiguous to'aircraft, upon theadvent of a crash landing.

Another object of this l.invention is to provide meansto close variouselements .in the aircraft While making thev crashlanding, such as topermit the `closure of circuits, therebypreventing the now .of current`from the generator, .from the battery,` and fromthe magnetos.

.A still further -`object of .this invention vis to perform the abovevmentioned functions by several selective means, one of whichispositioned forwardly of the fuselage of the aircraft, another of whichis. positioned .at the lower .surface of the aircraft fuselage, whileanother is positioned interior of the aircraft, whereby manual actuation.thereof maybe. effected if .found desirable.

A still yfurther object of Athis invention fis to `provide improvedmeans for carryingout the above described functions.

.Another purpose o'f this invention is to simultaneously spray acompound on the engine, eX- haust manifold and other .heated portions ofa conventional aircraft engine, and break a circuit formed by theconventional electrical system of anaircraft.

Anotherk object of this invention .is ,to vsupply a mass or weight-on apivoted arm of a switch, which mass actuates the pivoted arm. uponabrupt deceleration ofthe aircraft, thereby rendering the switchinoperative for completing the circuit.

A still further .object of this invention is to increase the safety incrash landingr of aircraft by immediately opening the circuit of theelectrical system of the aircraft, spraying lire .extin'guisher compoundover the hot portions of the `aircraft power plant, and, if desired,vimmediately Stopp-ing the supp-ly of vfuel to the aircraft engine, e

`Ancillary objects `and features of novelty will become apparent tothose skilled in the art, in following the description of .the preferredform of the invention, illustrated in the accompanying drawings,wherein:

4 Figure l is a partial section of a longitudinal elevation of a typicalaircraft fuselage showing various velements contiguous to the aircraftpower plant and the invention .affixed thereto;

'Figure ,2 Vis `an enlarged 'fragmentary sectional view illustratingportions ofthe linvention'which are shown in Figure 1;

Figure 3 vis a sectional View illustrating the switch forming a part ofthe present ,invention and taken substantially on .the line'3-3 ofFigure 7;

Figure 4 is another sectional view illustrating the switch .and takensubstantially on theV line 4 4 of .Figure 7 Figure 5 is asectional v-iewtaken substantially on the line 5-5 of Figure 4 and inthe Vdirection ofthearrows;

Figure 6 is an enlarged elevational view showing the weight orcounterweight utilized in association withthe switch;

Figure 7 is a sectional view taken Substantially on the line 'l-'I of.Figure 4 and in the ,direction of the arrows;

Figure 8 is a perspective viewshowinginsulating elements utilized inassociation with the invention; l

Figure 9 is a perspective view of a contact forming part of the switch,and

Figure 10 is a Yfragmentary elevational view taken in the direction ofthe arrow on the left side of Figure?.

'This invention has been developed to provide a device for the vpurposeof 'eliminating fire hazard at the time of crash by Switching off theelectrical system oi' a conventional aircraft,.op erating 'a masterswitch thereby rendering inoperative various electrical appurtenances,and spraying a nre extinguishing compound on the warm portions of theengine, as well as other portions `which are `likely to initiate a fire.

Referring primarily to Figure l, there is illustrated a conventionalaircraft indicated at iii having a fuselage .l2 with a fire Wall orpartition T4 therein. Of course, the various appurtenances `contiguousto aircraft vprime movers orv power plants for propeller operation arelocated within the fuselage.

An instrument .panel I8 is illustrated within the cabin of the aircraftand the control surface actuation means generally indicated at is-associated therewith. A boss 22 is `secured to 45 the instrument panel'I8 and. has an actuation -handle 24 extending therefrom. This actuationhandle has a cable 2B rigidly attached thereto which extends through asheath .28, attached to the interior surface (interior relative to thecabin 50 of the aircraft) of the. re wall or partition by means ofaconventional clamp 3B.

"Referring to Figure 2, it will be Seen that the cablef`2 terminates atand'issecured to a finger '32 which `forms-a portion-.ofi `a4 :crankgenerally 55 indicated at 34. Thisfcrank hasza plurality of fingers`3,2, 36 and `38;wl'1ich initiate'from a 'common center. Extendingthrough the common center is a pivot pin 40 which is secured to theinterior surface of the fire wall I4 by means of the brackets 42.

It may now be seen that upon actuation of the handle 24, the finger 32,and consequently the crank 34, is pivotally actuated.

The lower portion of the fuselage I2 is provided with a bracket 44having a pivot pin 46 associated therewith. Secured to this pivot pin isa rod or arm 48 which is seated in a suitable recess 50 provided in thelower portion of the fuselage for accommodation thereof. Securedadjacent the opposite end of the arm 48 is a perch 52 having one end ofa pitman 54 secured thereto. The opposite end of the pitman 54 is alsoconnected with the finger 32 for actuation of the crank 34. Thelowermost portion of the iire wall or partition I4 is provided with anotch 5B also for accommodating the rod 48.

An arm or rod 80 is slidably passed through an aperture `62 formed inthe forward portion of the fuselage I2 and a guide 64 is secured to theinner surface of the fuselage therefor. This guide has a sleeve 86formed integral therewith which accommodates a spring. The spring reactson the rod 60 for constantly biasing the rod exteriorly of the fuselage.Upon forcing the rod G0 inwardly of the fuselage |2 against the opposingaction of the spring (unshown) within the sleeve 66, the pitman 68 isurged (see Fig. 2) for actuation of the crank 34. The pitman 68 isconventionally connected in a manner peculiar to pitman reds to the rod60 and also to the finger 38 of the crank 34 which passes through anaperture 69 in the fire wall |4.

In recapitulation, it is seen that three means independently actuatableare provided for rotating the crank 34 about its common center or pivotpin 40. One means is utilizable from the cockpit or cabin of theaircraft, another means is rendered operative upon belly landings, whilethe third means is rendered operative upon crash landings wherein thenose of the aircraft approaches the ground in a forced landing.

Attention is now directed primarily to Figure 4 wherein there isdisclosed a view of a master switch having conductors I0 and I2terminating therein. These conductors are associated with the electricalsystem of the conventional aircraft in such a manner as to control theentire system. An insulation plate or sheet 'I4 is secured to the saidre wall or partition I4 by suitable means such as screws T6. Smallsleeves I9 are secured to the insulating element I4 and extend throughsuitable apertures provided in the partition I4 for accommodation of thescrews and also to insure insulation of the wires or conductors 'I0 and'I2 from the body of the aircraft. A second insulating plate B0 isjuxtaposed relative to the first-mentioned insulating plate 'I4 and ismaintained in place by the extension of the screws 16 into the suitableapertures 82, which may be internally threaded for locking accommodationof the screws.

A pair of substantially identical brackets, generally indicated at 84,are secured to the insulating plate by anchoring the tabs 8B in theslots 88 provided in the insulating plate 88 and also by reception ofsuitable screws through the apertures 90 which are ultimately seated inthe countersunk apertures 92 formed in the insulating plate 80. It willbe noted that the brackets, generally. indicated at 84, are providedwith spaced contacts 94 and 96, respectively, which 4 cooperate with thepivoted arm 98. The pivoted arm 98 is pivotally associated with a pin I00 which extends through a pair of these spaced contacts 04 and 86 andis frictionally maintained in the pair of contact arms 94 and 96 ofanother one of the brackets.

The said conductors 'I2 and 10, respectively. are secured to respectivebrackets 84 and the circuit is made through the medium of the knife orpivoted arm 98.

An apertured strap |02 is secured to the pivoted arm 98 and a frangibleor easily breakable connecting wire |04 is secured to the apertures inthe said aperture-d strap |02. This frangible element is also secured toa suitable perch or bracket |06 formed in the said re wall I4 formaintaining the said pivoted arm 98 in thek circuit-closing position.Due to the vibration of the aircraft in night and also due to aircurrents, this frangible element |04 is utilized for maintaining thepivoted arm 98 in the selected position, notwithstanding adverseconditions occurring in ying. Said strap |02 may be connected to thepivoted arm 98 with insulating material spacing these elements and alsoa suitable insulating material may be used in association with thebracket |06 for assurance of lack of transmission of current to theaircraft fuselage and body portions.

A weight or counterweight |08 is secured to the said pivoted arm 98 andis faced with a sheet of insulating material |09. This insulatingmaterial contacts the said re wall I4 until urged therefrom either by arelatively large shock of the entire aircraft or by means to bedescribed at this time.

An extension |I2 extends laterally from the counterweight |08 and thisextension is aligned With the cable |50, which in turn operates therocker arm |38. When the switch is operated in response to aircraftimpact without the aid of a push or pull control, the current is shutoff from the battery, magnetos, and generator. A suitable opening orrecess IIS is formed in the fire wall I4, whereby the roller ||4 as Wellas the nger 38 passes therethrough to be contacted by the insulator |09.By breaking the frangible connecting element |06, the arm 98 is allowedto move pivotally as disclosed in Figure 7.

In order to prevent the return of the pivoted arm 98 to the circuitclosing position, a closure |20 is connected with an extension |22 ofthe insulating sheet or plate 80. This closure is mounted by aconventional spring return hinge, |24, the arrangement being such toswing to the bracket 84 engaging position when the pivoted arm 98 swingsto the circuit breaking position.

It may now be seen that upon actuation of the handle 24, or either ofthe rods 60 or 48, the pivoted arm 98 is urged to the circuit breakingposition.

Simultaneously with the actuation of the switch described above, is theactuation of the device for spreading fire-extinguishing composition tovarious and sundry desired elements of the internal combustion engine orother aircraft prime mover system. Reference to Figure 2 discloses atank |25 or other suitable receptacle which is attached to the interiorof the fuselage I2 by means of a conventional bracket |28. A suitableand conventional valve |30 is connected with the outlet port of the tank|26 which may contain carbon dioxide, or compounds including carbondioxide and inert materials. A conduit andi'fzalffsuitabierbaiiie '-l3#is disposed overL the sprayerfconduitfi 32 "for directinglthe fire*extinguishingfcompoundfpverf-tlie desired' portions-"ofrelativelyhotlieads 2oi" the engine, and votherrelements. bracket! F35is secured within=theffuselage l2 `and' hasla'f rockerfar-m i [38pivotedffthereto- This `rocker llarmli'asl structural' elementse I?!Dfthereon frfadditional strengtht a'ndirigi'dityA andthei ter-.minal-per-tionsrf thefrockenarms areutilized for theapurposeffmaintaining cali-les'A or 4atl-ier"fierr-`iblefforce-transmittingzmeans;

Itmay; be seen-thatf'avcablel l42:is'secured`"tp tli'e'va'lve` t3 U?,extending over a conventional' pul- -lyf I 44,: tliencefoverf-aIsecondi-'conventional pulv-also securediv to ithe2 rocker arm'immediately-adj jacentflthesaid l' cable' i 42 landV terminates i in"nthe crank 34 by the means-"describedfhereinabovethevalve |30 will;be-1siinult'aneo'usly` actulated, thereby' permitting the' emissionfofi'ref extinguishing' composition from'A the tank: I'Zover selected?portions-1 of the-engine: In the vcourse are; iinl'turn;simultaneously#actuated @yV-ith; the

at this point'i that-any1apparatusorf devicewhicli is inherentlydangerous in a crash -ofanfaircraft .ina-yb'e rendered inoperative 'by`theutility of a `cable `connected to therocker" armAk `I 38 similarlytothecables^-|56 andi-581.

l In the event that a,relativelyrougliiandingis made h y; the aircraft,`l`tlie4 Weight "I0r8iis` maintaineddnplace by thefriction of thecontacts 94 and 9,6.andialso-by the frangilile"element;` tilt.Howevenfwhen a 'crash landing is` eiect'edlj the jar is rriucli`greater"an'd"the counterweightfis urged pivotally-with.theztpiiztedarm9B by the I meansffdescribed hereinabove.:

From the foregoing, a clear understanding of the operationAofithe-'inventionv is deemed ap- .,parent. Howeven it is understoodthat variations may be made such as the,.addition ofc elements as thepulley for guiding the flexible cable |5011erother suitablePeqniva-lentsmay be made. without departing from the spirit of the invention.Accordingly, limitation is sought only iiracicordance witlitlie scopeofA theifollowing claims. l

Having 'described the invention, what is claimed as newvis:` Y

l. In an aircraft'including' a fuselage having a partition thereinand'an electrical syst'enL-'a 'switcliehaving a pivoted"farm`Yl in theHelctrical attached tosaidpivoterlfarm,raninsuiatinggplatesecured' tosaid `weightv anduengagingxthe spartiztion', frangible; meansmaintaining;the-insulating plate: against 'I thel partition',:meansQextending through=.'sai'd fuselage ,foi-r:breakingsaid-frangible'.means :and for :actuation ofy vthefaslwitelr.. said' breakingA means:comprising aired; lr:afrcrankgpivoted to::said partition;andltconnectedtto saidrrod, onex end:- ofsaid crank` being;inffengagementawith saidinsu'lating plate.

' 3. In ancair'craf-t; including-a fuselagexihaving a i partition ftherein.; and :an:y felectricallsystemea switch havinglra. pivotedffarmtliexeleetricai system, electrically :insulating means interposedbetween 1 the. switchz and said: partition, xalweiglit attached tosaid..;pivoted army. Aan;insuiatiliigmlaft'e .secured toff'saidfweight-,rand "engaging ,.itliei'gpartition, frangilole` means?maintainingf. thexinsulating 1 plat-@against ttheJpartltionaineansextending throughsaid'` fuselage forebreakingfsaidaifrangible Ameans' andvfor 1 aetuationr. of" the ifswitch; said vbreaking means comprisingJaired; :az crankzpiyote'd tois'aidpartitlonrsandconnectedstoffsaidimad.; tonegendfofr:saidcrankilbeingzjinengagement with said insulatinguplatea lever pivoted .tovzisaid'fuselage, and `means':for:-transmitting:nieveirrent :of s'aidiflevertolsaidicrank;

4;.:nt2a'n .zaircra-f including afuselagerhaving l'.attached, toisaidepivotedsarmnam insulating plate isecure'dto saidirweightandfafengagingitnefzpartiL tion, fnangiblermeansv maintaining-wha:insulatingrplatef againsttthe partition;meanssextendingthrltmgh;saidfnselage: furl` `bre aking; said'ifrangibie )meansxsandiforc'sactuation r of? fthe ffswitch, vsaid breakingmeansfcclmpristug.;v arrod; a '.icrank '.pivoted toEsaidipartitiorr:andiconnectedstossaidntod, .'onezzendzofsasaidcrankcbeinginfengagemen th said insulating plate, a lever pivoted.toifsaid fuselage; means-:for transmittingrmovementiof `saidflevertti-.said1'crank, an'dmanual'ly operative vmeans.associatedrwithzsaidfcrarikvfora'actuaticn lthle'f'. f l

1.5;' Inearraircraft includingea fuselage havingeapartition.Ithereinleandi anf'electrical system, .-afswitchlliavingnafpiyotedfarm'in'e the: .electrical esystem,2electricallyffinslating means?. interposed betweentherswitchinndasaidzpartitiongsarweigiit fattachedftofzsaidapivotedarm aan:insulatingnalate secured ttorsaidi weights-and enga'gingf the 1 parti-'vtion, .fr-angiblermeans maintaining-the insulatl 'ingplat'e againstthe partition, 'means-extending tlfirciugli said fuselage forIbreakingisaid'fi'angfibl meansY and ifor 'actuation of the switch, saidbreakinglmeanscompi'isingr ai rod, a:l crank' piv'- pte'dto'fsai'd'fpartitionandlconnectedfitoisaidrd, one end" of said crank-A'be-in'g'iinL engagementwitli V'sai-'d insulating plate; ai tanksecur'ecll vwithinssa-i'd fuselageffor"storing asii're extinguishingcomposition, a valve secured to said tank, meanslactuated by said crankand connected with said valve for actuation of said valve simultaneouslywith the actuation of said switch.

6. In an aircraft including a fuselage having a partition therein and anelectrical system, aV switch having a pivoted arm in the electricalsystem, electrically insulating means interposed between the switch andsaid partition, a weight 7 attached to said pivoted arm, an insulatingplate secured to said Weight and' engaging the partition, frangiblemeans maintaining the insulating plate against the partition, meansextending through said fuselage for breaking said frangible means andfor actuation of the switch, said breaking means comprising a rod, acrankpivoted to said partition and connected to said rod, one end ofsaid crank being in engagement with said insulating plate, a tanksecured within said fuselage for storing a fire extinguishingcomposition, a valve secured to said tank, means actuate'dby said crankand connected with said valve for actuation of said valve simultaneouslywith the actuation of said switch, and a baiile secured in said fuselagefor directing issuing compound in predetermined directions. 7.Anaircraft including a fuselage having a partition therein and anelectrical system, a bracket secured within said fuselage, a rocker armpivoted to said bracket, a tank secured within said fuselage for storingfire extinguishing compound, an electrical switch including a pivotedarm and arranged to open the circuit of the electrical system,electrically insulating means `for securing said switch to saidpartition, means mounted upon said partition for actuating saidswitchand said rocker arm, Valve means secured to said tank, andflexible means connecting said rocker arm and said valve means.

8. An aircraft including a fuselage having a partition therein and anelectrical system, a bracket secured within said fuselage, a rocker farmpivoted to said bracket, a tank secured within said fuselage forlstoring fire extinguishing compound, an electrical switch including aplv'- oted arm and arranged to open the circuit of the electricalsystem, electrically insulating meansfor securing said switch to saidpartition, means mounted upon'said partition for actuating' said switchand said rocker arm, valve means secured to said tank, flexible meansconnecting saidrocker arm and said valve means,` said actuation meansincluding an arm pivoted to said fusela'ge'and extending from theexterior portion thereof.

9. An aircraft including a fuselage having a .partition therein and anelectrical' system, a bracket secured withinsaid fuselage, a rocker armpivoted to said bracket, a tank secured Within said fuselage for storingre extinguishing compound, an electrical switch-.including a pivoted armand arranged to open the circuit of the electrical system, electricallyinsulating means for securing said switch to said partition, meansmounted upon said partition for actuating said switch and said rockerarm, valve means secured to said tank, flexible means connecting saidrocker arm and said valve means, said actuation means including an armpivoted to said fuselage and extending from the exterior portionthereof, ay weight secured to the switch pivoted arm, frangible meanssecuring said weight to the partition, a crank having fingers pivoted tothe partition, said arm being connected to one said finger, and anothersaid finger engaging the weight. v

10. An aircraft including a fuselage having a partition therein and anelectrical system, a bracket secured within said fuselage, a rocker armpivoted to said bracket, a tank-secured within said fuselage for storingfire extinguishing compound, an electrical switch including a pivotedarm and arranged to open the circuit of the electrical system,electrically insulating means for securing said switch to saidpartition, means mounted upon said partition for actuating said switchand said rocker arm, Valve means secured to said tank, flexible meansconnecting said rocker,` arm and said valve means, said actuation meansincluding an arm pivoted to said fuselage and extending from theexterior portion thereof, a Weight secured to the switch pivoted arm,frangible means securing said weight to the partition, a crank havingfingers pivoted to the partition, said arm being connected to one ofsaid fingers, andk another said finger engaging the weight, arodextending through said fuselage. and link means connecting stillanother said finger and said rod.

11. An aircraft including a fuselage having a partition therein and anelectrical system with a generator, a bracket secured within saidlfuselage, a rocker rm pivoted to said bracket, a tank secured Withinsaid fuselage for storing re Yextinguishing compound, an electricalswitch including a pivoted arm and arranged to open-the circuit of theelectrical system, electrically insulating means for securing saidswitch to said partition, means mounted upon said fuselage for actuatingsaid switch and said rocker arm, valve means secured to said tank,flexible means conf necting said rocker arm and said valve means, andflexible means secured to said rocker arm and the generator forrendering the generator inoperativel simultaneously with the actuationof the switch. v

12. The combination of claim 10 and a bal secured within said fuselageadjacent said valve means for directing issuing composition inpredetermined paths.

13. The combination of claim 'l and means secured within said fuselagefor guiding said flexible means.

14. The combination of claim 10 and manually operative means foractuating said crank.

ROBERT H. HODGINS. CLIFFORD J. MCGILLIVRAY.

REFERENCES CITED The following references are of record in the file` ofthis patent:

UNITED STATES PATENTS Great Britain Aug. 20, k1925

